SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8332c9ba95ef637af347701c8f453da7728e2f2b4abf250fb2be154aca921ad7' 
  AND token = 'gwvibYqalS3JVAzPMU9L+C7s0iD+5u2/7zu3l30Eb6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}