SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b59f420ac3d97bedf7953d904fe900768bf98460e1c1158a847ad85c228f5e2b' 
  AND token = 'Zi8UrN8587So+Uv+3vXQ7oEzqGxPr+Z2LXLfD2Tm0ak=' 
  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"
    }
  }
}