SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '783ed6b77dafa05b556a52bc61441a7972ba47492f91803be49697ae6442686e' 
  AND token = 'Ig7IHDVBTF1Bx8L6siF0TsWlyQpD6IHRAEoTh2i2Lvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}