SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caca96c46278d55976898d870b88452f4b0e22444f19983a210d26c5b99de237' 
  AND token = 'hqsp7vT5kyspXm3olVtREy+MR9mqXBkw+mh1svFCK1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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