SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f83b6086dde9bc24ccfad6b921172d9ef06838d1ecbfaa38392bca8044144f2' 
  AND token = 'WJynNYDJ4bTc0O2fN2o5haier4vNUip3Bw9EMJFPUkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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