SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6257401c98141121585c77d581bc58c62946ff51232f612c2a7d36470a824873' 
  AND token = 'gvVe7a2RP1+Ho26zdjcA1/DijtVsHbZ42+tXyG1+rCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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