SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd01a1662b29b00c5bfccc2657d02979108c58b9448512d282930f6f3baac1840' 
  AND token = 'um6A0Wel1zP2GMGx3qrT2KFiDXcgrey4NNelbuvHIAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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