SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fce499a14eb39bf66c3c22da745e24cd02359c25480229740135b9ead1b10796' 
  AND token = 'vOBkNP+KXPwklnWLZjPwpDEpZx4gG+gWoK+TSX6EPWc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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