SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ecb796281b83270155781bb33c30b31bc5d89426c95943d04fe2ed762ae6bd8' 
  AND token = 'z6AMGwHgBGsNGFFVYebQksqS3OotfD6i/ZaON87+QSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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