SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2d8c7d7a745a821c7bf2018faabae139c2e90cea401b101027bdce9bd48f637' 
  AND token = 'xKnZKdqmZx9PGwvq+5ujYVk253tmgLI7G5g72aHCiE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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