SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '140c2e0db6a35bc14336ae56a6aed5e34034342a1df0a2cf0c13624e1976b49a' 
  AND token = 'BgyF/fErvKbahnQ2Kh0l4GrSsz4HMA8jKeBfBhHTRos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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