SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2a2895f8d1d4fbe131b5e9438bbedf64d0592410b84f546be9349659b15961a' 
  AND token = 'PRTyIej3guzeuvIv8sP9IPOzG2L0gCliye0p/itEv0w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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