SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '05183408665baa1eca62f4007efb19cd4f6fbd0beb0f553b91ef5b91e2fbfa0d' 
  AND token = '6+diqSaxTKMYGBEBCR+pbYf18kNLFQ8QQkoK65RuOyo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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