SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7602b9a349da26b90aa026a2f81841df7e2b0632da7af4c021ac4c94d7f4b311' 
  AND token = 'tHDQd51SOo6aBHTy6dRkcTU1JI48vNuMiwIK7gGc/Kk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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