SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3bc242b490cb6d8d982b0563a4b3f5bcad43eec67400a54aabadef0d33c4f38' 
  AND token = 'H1xg+p/LLWVJKU5ieIdJsiFCfwBvHiypJ0bup01s8SM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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