SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbc42abdebee823368810803d591f9788de7ce1e5e0d903791aee98f83a511ad' 
  AND token = 'uL7obwQUkdIVYf2KCFsdQY8FI2146eoxQ+SkCHM8gCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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