SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11dbb3a02e755a91cce3287da260a687e9095a5a76dbf4b21b481464f5ae79dd' 
  AND token = 'MDdBR/njH4MtVJkyz8MMU0dIcZ5NTH/+CMVffvmdsNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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