SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd9bb1dde244b6bab72f584e69f1e6592d43ec2f0c998f65ad74c6345569fe78' 
  AND token = 'ELmtxsbnPgjQv/fZKPEJlG6I8UOEespNJXX1DgVX9oI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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