SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79570da16fbb560d691d414893abec3a215adf27474454fc4d15e62c2a7a148f' 
  AND token = 'do3ozn7Kr5T2i3OSZJfnr/orBB4kDnVOTBXJHLT6DMk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}