SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f912fb96534ac3a1ac6f60e51f0eb379cf2d27c1e0445b9aebd22b81faad9951' 
  AND token = 'VMUNRPbcLRPli1iSsvxs9pvwmmTyRC45/twKDrEXp6s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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