SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ee397af1d4a942626561cf6cb936fd34e6048c7dd9852d8254abd8c4611c978f' 
  AND token = '0AqPfR27J7h2ATR7ygqvSt5NUospXzaUWKHrVg2Jl2U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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