SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27a99e993b0b8df2dfebb6fe9f2178aa1ed2db396a5fa300a00a462523e29192' 
  AND token = 'w4+iBIJeTDGCs44KS7Lmj6rvyUq9o9fHdwoTeYULk9U=' 
  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"
    }
  }
}