SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a74fc2199262dce23719beca46d0d193fa0b6b641b8accbc325e766f07d25618' 
  AND token = 'sJ/Dd0BIR0LNsprClVHG4tpRsiNCXusxrkTfIffCgs4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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