SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b01c2710b4097b9b0dd547f00e38dee87617541327931c5cfcd7f26f6269346' 
  AND token = '0yWpat5C+uSgmv02hzGNZR0R4MM/BMqlAeohZNZ/+3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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