SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce6470f727a92428ca7495a2573c5e85c260af4b6517a7c475b3296ee086d0fd' 
  AND token = 'uqMBlKIVXYu/nqsc0aFwz/bP7GMQrFARcvvpwgi7lFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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