SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e32569cb174b571b3f2c8f85c6d69d02cc7026620580fe2e940344a35dd4efe' 
  AND token = 'WKmMRCuRvARdG2YQkFTLYfTI2iT/Idl+dwVe2vh3Q4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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