SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6695387fc266403992270720edf850805f1e3ee991b10107b80a6a02f35fa8cf' 
  AND token = '2sbBR2O57r3Tt33YslDXfomlRD55KqjNVRFQfJJbxxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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