SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a87ccc331035c3115e8ab34186e31969304200778461d3afc1f76cf85d409eff' 
  AND token = '+xhCFCb/cTMEyBH3+dmaZQgupqJwgqljnrxs4Y6mIxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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