SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1e58fe8adff7c5d3bbb4bc4125a0af9da89a9633824b0e92caf919ec5b93dac' 
  AND token = 'ViE+FSz9zfX+iyyw8XOenfbPAHIWExUxW/VrOhBTmYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}