SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fca7f6cfc27669272dcb5197e7acf7c9dffc71ac4afb96c21dd4f7ac98b31d66' 
  AND token = 'BaIwqzFFMenkrMH3iWPVvSR1DqxSFfj8h5fMtECQmN0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00127

JSON explain

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