SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eab7c6e05ed3335a8dd31da48198e9c78ae181b550c7b982acd5854dec9d8dac' 
  AND token = '1WGrG1g7cIh++KgdMwvdqYg+geVgY7o0skNocaba7hs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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