SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca7f110f8d1324b5c7cbde0e4cebdf77caf4415c905534b4ee324164ae1ebdf3' 
  AND token = 'RBbFI1eOamSofdVKGyS21gXtrKIcNqNPHPqS3/CH0bA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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