SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52bf3065db9a1b716b68bcf55a4cb2c49e72018dcb9f1fefe3acbfadd752c38e' 
  AND token = 'sxTgzP1PQRI4m5RyUrqxStyScgpQ9DcNnXVb66lA7Ek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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