SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '666e44b3b5fc7bddccd4e2743fc15d30da205dcf7619e81a82e24c2648fba972' 
  AND token = 'ai4rQWPSRjLJesOIU7us/v9n/Ju3a7BbOPvAwFXm7mc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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