SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a1a685af589336439a6486d1d15dc802423a0d41f4b1a3ed2f64398378f8012' 
  AND token = 'FtOpcpv8OUEGb5quiC/Q2bnbSQjZstTjRwI++w7kNXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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