SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e0679481b680800a20f674463ed1112a256d70cd8c42d4aed1ec7431c3e2a0f' 
  AND token = 'Jwt6RIt1bfwo/nYtsYqT2aFXMV0o8LtgSxByA32S+FU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}