SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54851655eaed3033a8670f56c577032688b7758c96d9844ee75a3234ec0b8443' 
  AND token = 'uU0tfXWKz4+PdPWAo1vcFp12cSFTZojwkDaBmuCsK+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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