SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa85fd7008328f80e7f0167375f2f0c9ef81fb31f7ec60902b8345ab3917d739' 
  AND token = 'oBr6sh6OskeJn1rXBnNEcbcfFCAejEMzunCGDoq2WSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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