SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6edc8e7d1612b1b016b86f9925d57eec0716c0321c4a1dd420b0b7c54cb72832' 
  AND token = 'Uo5BW6coEtXrhnNAaxJnw/tzmpJwUYoczKT4JszBHpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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