SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d1f83b0aec2c3a4dbe1aa65f02f2474708535da14d0d47ddb3267916a30da66' 
  AND token = 'EXpKojhc1RdrI3aCnWvdquzFCHZGmP7lF6fifVl6JgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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