SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4adaf58c7c30faeb2d8c388b55f94f94bfbffb8fb8541d40b54d53c088271b8' 
  AND token = 'R7qiaLmw46V7wDR+2GezWJvzK7ALxgu+K0m+KsCVUI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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