SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74dfa95f0456a161c367029c68fd94bdb3de48874ed0bab0d7c1aacf36358138' 
  AND token = 'ejuEFWpkya1+Vlmq+aOnxC2cVL5IO7u6Nj59T07iL6o=' 
  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"
    }
  }
}