SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b26616b6a44ea0164129a6278ecaf6e2d39f5f5687714874a37fffa60c5e3163' 
  AND token = 'yCUrWm05c0f3tKPtNvxjUZqM4bLaqaRz35V7q5mG0Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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