SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '998d6744cf3381dcfe02668dfe1803909514af25cbea74670f77eb9799da2bc1' 
  AND token = 'TBgET1CjR9KrbqGSAGVu5Sei5wvuTrZz64z2/UFczoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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