SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a30db47167ecdacea10bdf1daac9e2c7fac0a899c2e79064b49c39247e99038e' 
  AND token = 'QK1exVZjv206CT+Dm48Tn8IHZg4MSo+zFO5SrxSRrOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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