SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9199034cd4d1ead7fa31b3a2e0dd39812201551ca977840f32e248517b32f643' 
  AND token = 'iWp/cJecj4j4nI1btE7eCLW1Cnw+ey3HhWLnhHFTx9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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